function download() {
    var fileName='';
    $.ajax({
        url:URL_PREFIX+"/excel/writeExcel",
        type:"get",
        async:false,
        statusCode:{
            200:function (data) {
                fileName=data;
            }
        }
    });
    window.location="http://39.97.125.68:8080/cost/download/"+fileName;
}